Home » News & Analysis » Japan’s Largest Warship Since World War II Takes To Sea

Japan’s Largest Warship Since World War II Takes To Sea

An image from a Sept. 23 video showing JS Izumo leaving Tokyo Bay on Sept. 23. YouTube

An image from a Sept. 23 video showing JS Izumo leaving Tokyo Bay on Sept. 23. YouTube

Japan’s largest warship since World War II has left for its first set of sea trials last week ahead of entering the Japanese Maritime Self Defense Force (JMSDF) fleet next year.

JS Izumo (DDH-183) departed Tokyo Bay on Sept. 23, as seen as in a video on YouTube, for the first round of what will be about six months of sea trials ahead of the ship’s commissioning next year, a JMSDF official told Jane’s Defence Weekly on Monday.

The 24,000-ton helicopter carrier is the first of two planned ships. Izumo will enter the JMSDF force next year. DDH-184 will enter the fleet in 2017, according to the Naval Institute’s Combat Fleet’s of the World.

The development pair of ships have fomented regional controversy since the formal start of the program, in part because of their strong resemblance to aircraft carriers

“It is an aircraft carrier, and Japan just called it a helicopter destroyer to downplay its aggressive nature,” Zhang Junshe with the People’s Liberation Army Naval Military Studies Research Institute told China Daily last year.

To Japan’s neighbors, even the name Izumo is a loaded word.

“The original Izumo, an armored cruiser that participated in the Battle of Tsushima, was purchased with reparations from the first Sino-Japanese War,” wrote USNI News contributor Kyle Mizokami last year.
“There is little doubt all parties, particularly the Chinese, are aware of the lineage.”

Though billed by Japan as primarily an anti-submarine warfare (ASW) and humanitarian and disaster relief (HADR) platform, its character is more in line with the U.S. Navy’s America-class of amphibious warships.


Izumo is large enough to field 14 helicopters and has the capacity to carry 400 troops. Japan could also field V-22 Osprey tilt-rotor aircraft from the ship. Ospreys are used by U.S. Marines to deploy troops from the sea and were successfully test onboard Japan’s Hyuga-class DDHs in 2013.

It’s conceivable the helicopter carrier could also accommodate the short takeoff/ vertical landing (STOVL) variants of the F-35 Lighting II Joint Strike Fighter (JSF) but Japan has said publically it has no intentions of fielding JSFs from the ships.

But — like the aviation centric America — the ship is not equipped with a well deck to deploy troops via landing craft.

Following World War II, the Imperial Japanese Navy was largely sunk and its pacifist constitution only allowed for military force in a direct threat to the country.

However in the last year, Japan’s Prime Minister Shinzo Abe has led a push to expand the scope of Japan’s military cooperation and its ability to develop its military export industry.

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Categories: News & Analysis
Sam LaGrone

About Sam LaGrone

Sam LaGrone is the USNI Online Editor at the U.S. Naval Institute.
He was formerly the U.S. Maritime Correspondent for the Washington D.C. bureau of Jane’s Defence Weekly and Jane’s Navy International. In his role he covered legislation, acquisition and operations for the Sea Services and spent time underway with the U.S. Navy, U.S. Marine Corps and the Canadian Navy.
Sam is a 2003 graduate of Virginia Military Institute.

  • TheTruth

    China sure gets worked up in a lather over a DDH. Maybe they could tone down the range of their DF-21 ASM?

  • 2IDSGT

    Just add F-35B, and watch the Chinese fizz.

  • Niccolo Machiavelli

    If they can have an AC of their own, why not Japan?

  • Ctrot

    China on Japanese “carrier”: Carriers are proof of Japans aggression!

    China on Chinese carrier: Carriers are purely for defensive purposes.

    • Screw China, they cant even build an Aircraft Carrier, nor can they build their own subs. China should be concerned, im glad to see this!

      • Rob C.

        its only matter of time until they get their flattops into production, they put alot of money into it. Everyone should be weary of them in coming decade.

  • Diogenes

    Being blasé’ about the Chinese DF-21D (CSS-5 Mod-4) Anti-ship ballistic missile is perhaps humorous, but it ain’t funny. It is the end of the US Navy carrier task force with all its implications unless all our new fangled weapons actually work as well as the Chinese claim the East Wind does. Unfortunately there is little public domain info of the real capabilities of the anti-ship variety so anecdotal presumptions is about all there is to work with. The US currently has nothing aboard a ship except cruise missiles that out ranges the semi-mobile launcher and would have to rely of the Air Force (heaven forbid), or first strike missiles from close in subs to defeat it in a meaningful way – if they can find them. Otherwise the folks who claim 100,000 ton steel ships can be stealthy better be right. CVNs don’t mean much if they have to drive around at 50 MPH 900 miles of an enemy’s shore just to avoid getting sunk. Sometime ago the US said the Chinese had about 80 of the weapons with both a conventional and nuclear capability. The Reds have been learning from us since Billy Mitchell and Claire Chennault showed them the potential of aviation that US Marine aviators drove home at the Frozen Chosin. Our guys will have a much rougher time ever hammering them that way again. The Japanese don’t seem to have learned a thing since then except big looks good on TV. Scoffing at Chinese capabilities brings to mind the American perception of Japanese capabilities in 1941 before they handed us our heads. Oh yeah, add the F-35B and watch it disappear along with the Izumo. It should stick to the humanitarian missions delegated to it.

    • keijhae

      Very long fairytale story of yours. 🙂

    • Paul

      Diogenes, you are very condescending indeed… for someone who can’t decide which side of his mouth he wants to talk out of… You talk about the DF-21 being the end of our carriers, but then lecture us on how the technology is unknown.
      Just so you know, what IS known is that our carrier battlegroup is WELL equipped to handle the DF-21 – SM-3s deployed with AEGIS cruisers (they took out a PIECE of a satellite that the Chinese couldn’t completely take out) – . Tomahawks fired from subs, for taking out the DF-21 launchers – F-18s doing hunt/kill sorties ; and I won’t even go into what kind of problem a single pack of F-22s and B-2s would be to ANY DF-21 launch plan.
      The DF-21 is scary… up until it’s NOT.

      • rick

        you actually read all that?

  • Strategist

    VSTOL F-35 is unlikely to be employed on this platform unless the deck is rated for the enormous heat produced. Australia’s LHD is unlikely to have F-35 as the deck will melt after a limited number of deck events.

    • rick

      they have amazing ceramic and other heat repelling materials, nowadays its no problem to coat surfaces with exotic stuff.

  • NofDen

    Japan was brutal in China, they killed at least 4 million Chinese from 1937-1945.
    When they took the city of Nanking they murdered 300,000 chinese.
    I understand why the Chinese are uneasy about Japan arming themselves.
    I think they should though, the Chinese are building many warships also.

    • old guy

      I saw a Chinese film, last year, where kindergarteners and first graders were playing a combat game and Japan was the stated enemy. Scary.

      • FrenchFriar


        • old guy

          Sorry, don’t have, but my wife and I think we saw it on aPBS channel. If you find it, we would like link too.

    • tayronachan

      The Japanese were brutal. What happened in Nanking won’t be forgoten by the Chinese.

    • illusive

      Does that have anything to do with this article, I could say that the Chinese Communist government were responsible for nearly 50 million Chinese deaths

    • oz’s wizard

      When does history slide off into the sunset? When does future generations stop paying for the sins of the past? When can the Japanese defend themselves? My answer to all three is NOW…….

  • old guy

    I saw a look down shot, months ago, but I can’t find it now. It showed what I believe was the indented foundation for a catapult. Does anyone else know of it?

  • Secundius

    A Large Gator-Freighter, MAYBE. An Aircraft Carrier, NO.

  • omegatalon

    China has nothing to worry about unless Japan begins ordering F-35B VSTOL fighter jets and while the F-35B generates a lot of heat; they can build special areas on deck fr where the F-35B could land as this is what the US Navy needs to do.

  • CaptainParker

    The Kido Butai appears to be rising from the ashes of its WWII predecessor just like the phoenix. This time, however, they are on the good guy’s side.

  • Secundius

    Unless they modify her with an “Angled Flight Deck”, she’s never going to operate anything other then the F/AV-35B’s or AV-8A/B’s.

  • FU

    japans secret weapons were gundams hidden under the ocean lol..

  • NavySubNuke

    Give them 3 years and they will be buying some F-35B’s for her and her sister. Using them as helo-carriers for asw and amphib ops is fine – but it is hard to imagine Japan not wanting to give them more teeth than that.

  • Rob C.

    Izuma is finally going to sea. I wish they stop calling the darn thing a Helicopter Destroyer, their not fooling anyone but people reading piece a paper without pictures.

    The ship looks fine, but i think China should be more worried about how many and how effective the ship’s compliment of Helios are firing torpedoes at potential submarines. Izuma is symbol, not as effective everyone hyping it. If Chinese get their anti-carrier ballistic missiles working, more importantly those russian rocket powered torpedos going. Izuma may be in need of effective escorts.

    I wonder if the Japanese architects designed the ship’s flight deck to handle the super heat the F-35Bs put out? It took some serious modifications to the Wasp Class to handle that birds hot exhaust from melting the flightdeck.

  • the great kazoo

    what did they think the Japs were going to do when they started eyeballing all their islands?


    That ship looks like its intended to quickly wipe out any contingent of Chinese troops trying to occupy an uninhabited island.

  • Paul Rayment

    Nice Boat…..be good to see what happens when ISIS decides to take on Nippon!

  • Chesapeakeguy

    Some on here have mentioned China’s supposed ability to take out ships with ballistic missiles. I use the word ‘supposed’ because nobody knows if they indeed have that capability. While one should never underestimate a society that has been around for so many thousands of years, some common sense needs to be applied too. Much of what China shows in the way of technological progress is the result of them stealing it, or having it provided to them by others who stole it. They are still a nation that is overwhelmingly comprised of peasants. Yes, they are making a splash, but they obviously have a long ways to go. About that ballistic missile technology that can (supposedly) take out carriers, I ask this: do WE, or our allies, have a similar capability? Because if we do not, I find it hard to believe the Chinese can develop one. They would invariably have to acquire that means externally. If we don’t have it, I personally doubt that they do!

    One other important thing here: What will be the reaction to ANYTHING in the way of a ballistic missile launch towards ANY target? And it stands to reason that any launch will involve several missiles, in an attempt to ensure the target is indeed taken out. Will said missiles be ‘allowed’ to ‘land’ (assuming that no defensive systems will be available to try to take them down) to see if they are ‘just’ conventionally armed? Or might someone make a determination that any ballistic missile launch will carry a nuke warhead, and perhaps trigger a more ‘automatic’ response? Those are concerns that EVERYBODY, including our side, will always have to consider if the use of such weapons, even in a conventional mode, are considered. And there have been proposals on our side about developing ‘bunker busting’ sub-launched missiles with conventional warheads. ALL had better be darned careful in how they proceed here, or that they get what they wish for.

  • Gray Stoke

    When talking about the Chinese aircraft carrier, would you please focus on what capabilities its embarked AIRCRAFT wing can bring to the table.
    If Chinese naval aviation can duke it out with American aircraft, that would be worrisome.

  • muzzleloader

    To those who continue to mention the brutality of Imperial japan, I say yes, they were brutal and barbaric. I think we can say that Imperial Japan had total destruction of it’s war machine it, industrial capability, and retribution of it’s leadership, both military and civilian. Since then Japan has been a steadfastly loyal and able ally, with a Constitution that has been for all intents, pacifist.
    That said, any sovereign nation has the right to defend them selves. Japan has a world class navy and Air force for that purpose. They also have a powerful and increasingly belligerent neighbor. I f the U.S. ever needed the ability Japan can field it is now.
    If Japan wants to build assets to add to their ability, CV’s included, I say Hooza!

  • Thomas

    Article is misleading. Izumo’s flight decks can’t handle the F-35s exhaust.

  • Viking

    Sure, Japan and US are allies now, but let’s see the comments here when they’re not (you know like during the last WW).

  • Antikythera

    As long as they don’t name the next 6 Akagi, Hiryu, the Kaga, Shokaku, Soryu & the Zuikaka I think were good!

    • MrSilenceDogood

      The next is named Kaga.

  • Gary Grimm

    I am confident the Sailors aboard this ship felt ten feet tall.

  • Roger Elliott

    finally, The US might be allowing Japan to have something other than a defence force!